FIG. 10 shows a perspective view of a conventional buckle having an ordinary structure.
A buckle connected to one of the watch bands 10 comprises a frame 20 and a tongue 40. An end of the other band 30 is inserted into the frame 20 from the underside of the buckle. The band 30 is pulled in the reverse direction at the frame 20. The tongue 40 is engaged with one of adjusting holes 30a of the band 30 at a desired length. Thus, the length of the band is easily adjustable and the band is worn in good feeling.
However, in such a conventional buckle, the band must be attentively inserted in the frame of the buckle from the underside thereof. Otherwise, the buckle may disengage, and the watch may drop. Furthermore, the frame and the tongue rub the surface of the band, causing it to hurt and the life of the band to shorten.
Japanese Utility Model Application Laid-open No. 3-127519 discloses a buckle which may eliminate the above mentioned defects. As shown in FIGS. 11 and 12, the buckle comprises a rectangular frame 31 in which a first band 42 having a plurality of engaging holes 44 is inserted, a middle plate 46 rotatably connected to an end of the frame, and a bottom plate 48 rotatably connected to the middle plate and a second band 50. The frame 31 has an inner space approximately equal to the thickness of the first band 42. An end of the middle plate 46 is connected to a connecting portion 34 secured to the underside of the frame 31 with a pin 32. A tongue 36 is fixed to the pin 32 to be rotatably supported by the connecting portion 34, and engaged with one of the engaging holes 44 of the first band 42. The middle plate 46 further has an engaging recess 46a to be engaged with an engaging portion 56 provided on the bottom plate 48. The second band 50 is connected to an end of the bottom plate 48 through a connecting link 52.
In order to use the buckle, the first band 42 is inserted into the frame 31 and the tongue 36 is rotated and inserted into one of the holes 44 of the band at a preferable length so that the band 42 is secured in the frame 31. The frame 31 is pressed against the bottom plate 48 so that the recess 46a of the middle plate 46 engages with the engaging portion 56 of the bottom plate 48. If a tension is exerted on the band 42 for expanding the band, the tongue 36 is abutted on a side 46b of the middle plate 46, thereby preventing the band from expanding. In order to disengage the buckle, the frame 31 is picked up and pulled up from the bottom plate 48. Thus, the middle plate is disengaged from the bottom plate 48, so that the ring formed by the bands 42 and 53 is expanded. Therefore, the watch can be removed from the wrist.
In the buckle, since the effective length of the band is adjusted once to a desired length, the band is not rubbed by the tongue. Thus, the band is not hurt. However, it is not easy to pick up the frame 31 from the bottom plate with fingers because of the thin frame.
An object of the present invention is to provide a buckle for watch bands in which the length of the band can be easily adjustable.
Another object of the present invention is to provide a buckle for watch bands which is easily operable.